wogihao

No worries,

When you can do 50 easy on each set then make alterations.

For example,

Pushups - hand placement variations lateral (wide, narrow, knuckles, wrist, on a basket ball)
- foot placement variations (off a chair, a stack of books, against a wall, balaced on a ball)
- hand placement variation vertical (hands on raised blocks, clapping, single arm)

situps - knee to elbow (russian twists)
- situps off a blocks

leg rases - brace a object between your legs (a basket ball).

ect....